'87 engine in '79 SC, advise and tips please

[911cousins]

Hi all,


Does anyone know if there is an ' how to' manual to get a '87 170kW engine into a '79 SC car that covers all the different elements?
This is what I have done so far.
Engine
I have found what I hope to be a good donor engine (leak test came out great)
I have done the maintenance on the 'triangle of death' and the metal pieces around the engine are about to come back from the powder coater.
After inspection, I was worried about the full lines (the ones that are actually on the engine itself) so ordered new ones and I am about to install them

Gearbox
Chose to stick with the 915 gearbox (for it doesn't require work on the body of the SC) It is being overhauled by an expert and prepped to fit the 3.2 (sensor gaps)

Clutch
I believe I have all the parts and gearbox expert will help putting it all together.

Electrics
I found a harness and ECU and have drilled a hole to guide the wires to the back.
Wires to the back are now ready (used the tiny room next to the shock absorber to bring them up)

Advise requested
I have read and absorbed Marc and Chris' conversion posts (thank you, very helpful) but as I am not very knowledgable on Porsches (first timer), any additional advise is more than welcome.

For instance, I now need to install the ECU, ECU relay and altitude sensor (never knew I needed one..)
Living in Holland with the rain and all and being a targa, I am looking for tips how best to do that. Should I drill holes in the bottom or not? Arguments please.

I also need to sort out the wiring to the front. Assistance/pictures and tips are welcome. Do i need to change stuff on my tachometer for instance?

And then when all the prep is done and the engine+gbox go in, what should I expect with regard to full lines and oil lines. will they fit? is it recommendable to replace the fuel lines that are still in my SC while the engine os out? (looks like a complex project). What else should I do 'while I am there...'

Lots of questions I know but i hope that at least on some of them, I receive some responses. Many thanks in advance,

Hans

[Trackrash]

Although most of this has been covered. It may be difficult to search all the answers here.

I will say that the trans case will have to be modified to allow the timing sensors to work on the flywheel.

You could start a thread in the 911 Technical Forum with pictures of your car and steps of your progress. Others will help.

If there is a comprehensive thread in existence maybe someone will chime in with the link.

[911cousins]

Hi Gordon,

Thanks for your response, I think I will do just that!

Cheers, Hans

[Walt Fricke]

Your tach will now get its signal from the ECU. A wiring diagram will tell you what pin on the ECU or otherwise sends that signal. Should be easy to reroute some of the existing tach wire to connect to the ECU.

Having wiring diagrams for both cars will be very helpful in sorting out how to connect things.

If this were a race car, mounting these electronic components on the rear firewall, well up from where water might pool, would be an option. For a street car, measure clearances under the driver's seat. You should be able to make a bracket which you can fasten to the floor in a leak proof manner, and mount the ECU etc on top of that. If your car falls into a canal, nothing will help anyway, but keeping things a bit above the floor makes sense.

Oil lines depend somewhat on your exhaust system. Many of us like to convert to SSIs or early 911 manifolds, and use the oil crossover pipe which runs under the bell housing of the transmission, as the '72-3 did. But both your engines came with the pipe from the outlet of the oil pump to the cooler/tank running around the rear of the engine (because the right bank exhaust crosses over to the left side under the bell housing area), so this should all hook up easily enough.

[Flat6pac]

There is a white, flat 4prong connector that lays out under the hood in the main vDME harness.
2 solid black, 1 yellow (usually) and a black/purple
One black ohms to the DME relay
1 black is upshift light in Carrera tach
Black/ purple goes to back of tach replacing the black/purple there.

Fuel pump drive wire wires to the top of the fuse for fuel pump. Remove the original pump wiring from the relay and tape it out. Red Relay is no longer used in this application
Wire your coil wire from emergency lights that stay on when the engine cranks so there is ignition
The coil ground goes back to ground at the brain
That’s just off the top of my head, I’d have to look up the rest
Bruce

[911cousins]

Thank you Walt and Bruce, your comments are highly appreciated. I found out that the wiring was way above my level skills so decided to let the local Porsche garage work on it and they did a perfect job.
So this topic can be closed, the focus is now on improving the ride of the car!

Many thanks, H

[Peter M]

Hans,

What do you want to do longer term?

I guess by putting a 3.2 into a SC you're not a purist and suspect you have ITB fantasies or something similar for later on.

Consequently I suggest you sell the 3.2 Motronic ECU and 3.2 engine harness and buy yourself a modern fully tuneable aftermarket ECU such as Link, an unterminated harness and a handful of sensors and set the engine up that way.

This will give you an idea of what I'm talking about:
https://rasantproducts.com/content/Manuals/Rasant_Products_Engine_Management_Installation(ITB ).pdf

The benefits are:
Not tied to old and difficult to tune ECU
Can dump the AFM and enjoy the responsiveness,
Can easily tune for ITB's, twin plugs or hot cams if you want to go that way.
No struggle to try and integrate two standard Porsche harnesses
You can pick and choose what sensors you want to run
Opens up the possibility of DBW, cruise control, data logging, knock sensors, flex fuel etc.

Disadvantages?
I can't think of any except you'll need to tune it to get it running.

Just a thought!

[911cousins]

Hi Peter,

Thanks for the tip. Actually, my thoughts were going in a slightly different direction.

Let me explain.
The original 3.0 SC engine that came with the car has three studs broken. I had a local Porsche expert dissemble the engine and measure stuff up and I learned that other parts were also worn and needed to be replaced.
All in all, I was looking at an expensive, time consuming repair that would result in a very good, very new, but still relatively underperforming, unattractive 180 bhp (Calif.) CIS engine.
It was quicker and more cost effective (and fun) to put in a (german) 3.2 / 231 bhp / 170kW engine, ECU and harness etc. and as a bonus, I gained almost 30% power output as well.
So this was completed last September, engine runs great and I have been focussing on the suspension since. Now that all that is renewed as well and i don't have to steer to keep the car on a straight line anymore, my focus goes back to the original engine + CIS I still have in my garage.

I now bought myself time and consider to have that engine rebuild (slowly to meet my budget limits) but to what specs?
I definitely do not want to go back in power output so I am checking this forum now for options. Ideally, I would like to convert my 3.0 engine into a 3.2/170kW engine, add SSI's and then sell the 3.2 block I bought last year. That way, I have matching numbers, a new engine and great power output.

Any tips are welcome!

[Walt Fricke]

Do matching engine case/chassis numbers matter to purchasers who care about such things if the engine has been highly modified (as in a 3.2 instead of a 3.0?)

Do 3.2 blocks sell for more than 3.0s these days? Other than the oil drain plug system (which late 3.0s had also, and is more of a visual thing if hot rodding an engine than something you have to account for), aren't these blocks interchangeable, or close enough as not to matter?

[mepstein]

Do matching engine case/chassis numbers matter to purchasers who care about such things if the engine has been highly modified (as in a 3.2 instead of a 3.0?

For some, yes. Singer makes a point that their cars are matching numbers. I was told by a longtime Porsche mechanic that matching numbers on a 356 ment that all the individually numbered body panels matched, which meant no major accidents or tomfoolery. Matching engine and trans numbers, whatever, I could care less. Date matching wheels - yawn. But that's me and whatever floats your boat.

Do 3.2 blocks sell for more than 3.0s these days? Other than the oil drain plug system (which late 3.0s had also, and is more of a visual thing if hot rodding an engine than something you have to account for), aren't these blocks interchangeable, or close enough as not to matter?

I'm not sure the blocks sell for more but the engines get $2-3K more due to the Motronic vs CIS